Pregnant or not

Hi I'm new here and truly hoping someone can shime some light for Me ? I was on the evra patch and had took it almost correctly but last month 2/8/12. I had a very light and short period and then this "brake " 6/9/12 I didn't bleed at all ? So I rang my doc and he suggested I come of the patch till we figger out why I missed you see iv felt/feel pregnant ! Tiard emotional faint sick lost acid ? Light tummycramps low down . It is now the 18/9/12 and iv done 2 negative pregnancy tests (1miday and 1first thing)  and also a lab test from the docs that was negative so been today to docs and she had done a blood test to check for pregnancy. I'm just so concussed want to know as its been 2 weeks since iv had a patch on and having regular intercourse as we (hubby and I ) have decided we want our baby that we think we have can anyone understand that ?  So aswell as advice  on my situation I'm a or could I still be pregnant can you please help me if I didn't bleed this month will I it still be the best time to catch thesecond week after my "what would of been" period ???